1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to an image display apparatus, and more particularly, to controlling over-current in an image display apparatus, in which an operation of a main circuit unit can be prevented from being interrupted due to an unnecessary power cutoff or electric current limit which may be caused by a sensitive operation of an over-current protection circuit.
2. Description of the Related Art
FIG. 1 is a block diagram schematically showing a configuration of a related art image display apparatus.
Referring to FIG. 1, a related art image display apparatus (for example, a liquid crystal display (LCD) television (TV)) includes a lighting unit 130 which includes a lamp unit and illuminates light onto a display screen, a power supply unit 120 which supplies electric power to drive the lamp unit of the lighting unit 130, and a main circuit unit 110 which outputs a brightness control signal to control brightness of the lighting unit 130, and controls the power supply unit 120.
In the related art image display apparatus, electric current or voltage supplied from the power supply unit 120 to the lamp unit of the lighting unit 130 is detected. If the detected electric current or voltage is abnormal, a protection circuit (not shown) is made to operate. In the case that the protection circuit includes only a detection circuit which performs a detection operation in proportion to the electric current, even the instantaneous electric current which is excessively applied by an abnormal oscillation which may occur because of the low ambient temperature is recognized as an over-current even if it is not the electric current which can destruct an actual circuit.
Further, in the case that an abnormal oscillation operating frequency is very fast, the protection circuit is made to operate without being reset via a recharging procedure even by a charge and discharge timing operation. Also, an abnormal brightness control signal is output by fault of a brightness control circuit (not shown) in the main circuit unit 110 to cause the power supply unit 120 to supply over-current to the lamp unit. Even in this case, the protection circuit operates to control a cutoff operation of electric power or a restricting operation of electric current. As a result, the operation of the main circuit unit 110 may be unnecessarily interrupted.